A Nationwide Analysis of the Outcomes Among Hospitalized Patients with Heparin Induced Thrombocytopenia and Concomitant COVID-19 Infection

Background

Heparin induced thrombocytopenia (HIT) and COVID-19 infection are independently associated with thromboembolic complications. Our study aims to assess outcomes among hospitalised patients with concomitant HIT and COVID-19 infection, since data among this subgroup is lacking.

Methods

We utilized the 2018-2020 National Inpatient Sample (NIS) Database in conducting a retrospective cohort study. We identified patients who have heparin induced thrombocytopenia (HIT) and COVID-19 infection using appropriate ICD-10 CM codes. We stratified patients based on the presence or absence of COVID-19 infection. A survey multivariable logistic and linear regression analysis was used to calculate adjusted odds ratios (ORs) for the primary and secondary outcomes. A p value of <0.05 was considered statistically significant. The aim of this study was to investigate the impact of COVID-19 infection on in-hospital mortality, hospital LOS, total hospitalization charge and risk for arterial or venous thrombosis among hospitalized patients with HIT.

Results

We identified a total of 9896 hospitalized patients with heparin-induced thrombocytopenia (HIT), of which 7.68% (760/9896) had concomitant COVID-19 infection. The overall in-hospital mortality among those hospitalized patients with HIT was 17.14% (1695/9896). Among those with concomitant COVID-19 infection, the mortality rate was significantly higher at 50% (380/760, p=0.001). Further, compared to those without COVID-19 infection, those with concomitant COVID-19 infection had a significantly longer median LOS (21 days vs 11 days, p=0.001) and higher total hospitalization charge ($292,325 vs $143,972, p=0.001). Utilizing a stepwise survey multivariable logistic regression model that adjusted for patient and hospital level confounders, COVID-19 infection was found to be an independent predictor of increased in-hospital mortality (adjusted OR 5.13; 95% confidence interval [CI], 3.36-7.84; p=0.001), longer LOS (adjusted OR 6.21; 95% confidence interval [CI], 3.56-8.86; p=0.001) and higher total hospitalization charge (p=0.001). However, it was not significantly associated with increased risk for arterial (adjusted OR 0.72; 95% confidence interval [CI], 0.18-2.83; p=0.63) or venous (adjusted OR 0.91; 95% confidence interval [CI], 0.48-1.74; p=0.79) thrombosis.

Conclusion

Our analysis showed that among hospitalized patients with HIT, concomitant COVID-19 infection increased the risk for in-hospital mortality, longer LOS and higher total hospitalization charge, however, it did not significantly increase the risk for the development of arterial and venous thrombosis. Prospective studies with control of possible confounders are warranted in order to better describe these associations.